Control system



THEODORE H. SCHOEPF, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WEST-INGHOUSE ELECTRIC AND MANUFACTURING COMPANY,

PENNSYLVANIA.

A CORPORATION OF CONTROL SYSTEM.

new and useful Improvement in Control Systems, of which the following isa specification.

My invention relates to control systems for electrically propelledvehicles and par-l ticularly to control systems for electrically drivenmotor trucks which are provided' with storage batteries.

One object of my invention is to provid a control system of theabove'indicated character that shall insure a safe and economicaloperationof the motor or motors contained therein.

Another object of 'my invention is to.pro

vide a motor truck having a series-wound propelling motor, with meansfor insuring a safe operating speed of the motor in case the` same berelieved of the load thereon by the lrelease of the clutch, as whenchanging the transmitting gear. y

More specifically, my invention consists of an electric vehicle providedwith a ser1eswound propelling motor and a storage batj teiy for excitingthe motor and for additionally exciting the field lwinding in case themotor be relieved of the load thereon.- A clutch is provided fortransmitting the driving effort of the motor to the vehicle wheels. Aswitch is disposed adjacent to the clutch and is adapted to be operatedthereby. The switch connects a portion of the battery to the field;windings for additionally exciting the saine and thus prevent anexcessive motor speed in case the clutch is released and the motor isrelieved of the load thereon.

In the accompanying drawing illustrating my invention, Figure 1 is adiagrammatic view of a control` system constructed in accordance with myinvention, and Fig. 2 is a modified control system.

The motor truck 1 is provided with front Y wheels '2 (one only beingshown) and driving wheels 3 (one only being shown) which are mounted ona driving axle 1. A driving shaft 5, having a clutch 6 interposedintermediate its ends, is connected to the driving axle 4 by means ofbevel gears 7 and 8 which form a portion of a differential-gear. A leverI9, connected to a rod 10, is adapted to control the operation of theclutch 6. In

means of a master controller MC1.

specification of Letters Patent. Patented Sept. 16, 1919.

Application filed May 8, 1916.

Serial No. 96,140.

portion 24 and an auxiliary portion 24a and to be controlled by almaster controllerl MC. The master controlleriMC embodies a contactsegment 25 which is adapted to engage contact fingers 26 and 27 and acontact seglment 28 which is adapted to engage contact fingers 29, 30,31, 32, 33 and 34: to short cir- .cuit resistors R1, R2, R3 and R4 whenmoved to positions o, Z), c, d and e. A ytwopole, double-throwswitch 35,having switch blades 36, is adapted to connect contact terminals 37 and38 and 39 andAtOto complete circuits from thestorage battery 23 to the Amotor 2O when in the position shown.

When the switch is thrown to its reverse position, the switch blades 36connect contact :terminals 38 and 43 and d() and 44 to complete acircuit from the storage battery 23 to 'a charging receptacle 45.

Referring to Fig. 2 oit the drawing, a motor 50 having an armature 51and a iield winding 52, is adapted to be energized by a storage battery53 and to be governed by The master controller embodies a contact segment 54: which is adapted to engage contact ingers 55, 56, 57, 58, 59and 60 to short, circuit resistors R5, R6, R7 and R8 which are includedinthe circuit/ot the motor 50. A three-pole, double-throw switch 461,having blades 62, 63 and 64, is adapted to joint contact terminals 65and 66, 67 and 68, and 69 and to connect the motor 50 to the storagebattery 53 when in the position shown. 1When the switch is moved to itsreverse posi-V tion', the switch blades 62 and respectively join contactterminals 66 and 68 to Contact terminals 71 and 72 so to complete acircuit from the battery 53 to a charging receptacle 73.

`Although the motor truck 1 is only partially illustrated, it is to ybe'understood that the same may be provided witli-the usual transmissionand diierential gears common to motor cars. In order to simplify thedrawing, no means is shown for reversing the field winding relative tothearmature winding in case it is desired to reverse the moto-r.

Considering the system illustrated in Fig. 1 to be in the positionshown, the operation ot the same may be as follows. In moving the mastercontroller MC to position a, two circuits are completed, one circuitextending from the auxiliary battery portion 24a through the fieldwinding 22 and the sec- .ond circuit extending from the complete battery23 through the motor 20. The first circuit may be traced from oneterminal of the battery portion 24aj through contact fingers 26 and 27,which are bridged by the controller segment 25, contact terminals 12 and13, which are bridged by the contact segment 11, motor-field winding 22and contact' terminals,A 39 and 40, which are bridged by the switchblade 36, to the other terminal of the battery portion 24a. The secondcircuit may be traced from one terminal of the battery 23 throughcontact terminals 37 and 38, which are bridged by a switch blade 36,contact fingers 29 and 30 which are bridged by the controller segment28, resistors R1, R2, R3 and Ri, motor 20, and contact terminals 39 and40, which arebridged by a switch blade 36, to the other terminal of thebattery 23. Thus, the serieswound motor 2() is connected in series withthe. battery 23, and the battery portion 24a. is connected toadditionally energize field winding 22 in order to prevent an excessivespeed ot the motor, as the same is running without a load thereon. Inmoving the controller to positions ZJ, c, d and e, the resistors R1, R2,R3 and R4 are suceessivelyexeluded from the motor circuit.

In case it is desired to start the motor car 1, the lever 9 is operatedto throw the clutch 6 into its operative position. In moving the clutch6 to its operative position, the

contact segment 11 is disengaged from the contact terminals 12 and 13 tobreak the circuit from the battery portiJn 24a through the iield windingIt, during the opera- Y tion ot' the motor oar, the clutch be released,the contact segment 11 again bridges the contact terminals 12 and 13 toagain establish a circuit from the battery portion 24a through the iieldwinding Thus, an excessive speed of the motor 20, by reason of the loadbeing removed therefrom, is prevented..

In case'it is desired to charge the battery 23, the switch 35 is thrownto its reverse position so that one switch blade 36 bridges the contactterminals 38 and i3 and the second switch blade 3G bridges the contactterminals /10 and 441. A circuit is completed that may be traced fromthe charging receptacle 45 through contact tern'iinals et() and Lilwhich are bridged by the switch blade 36,` battery 23 and contactterminals 38 and 43, which are bridged by the switch blade 36, to thebattery-charging receptacle 45.

Considering the system illustrated in Fig. 2 to be in the positionshown, the operation of the same may be as follows. In moving the mastercontroller MC1 to position a, a circuit is completed from the battery 53through the motor 50, which may be traced from one terminal ot' thebattery through contact terminals 65 :and 66, which are bridged by theswitch blade 62, contact fingers 55 and v56, which are bridged by thecontroller segment 54, resistors R5, R6, R7 and R8, motor 50 and thecontact terminals 67 and 68, which are bridged by the switch blade 63,to the other terminal of the battery 53. A second circuit is completedthrough a portion 53a ot' the battery 53 which may be tracedfrom the oneterminal of the battery portion 53a throughcontact terminals 69 and 70,which are bridged by the switch blade 64, contact terminals 18 and 19,which are bridged by the contact terminal 17, field winding 52 and thecontact terminals 67 and 68, which are bridged by the switch blade 63,to the other terminal ot' the battery portion 53a. Thus, the motor 50 isenergized by the complete battery 53, and the field winding 52 isadditionally energized by the battery portion In moving the mastercontroller MC1 through positions 5, c, (Z and e, the resistors R5, R6,R7 and R8 are successively exA eluded from theycircuit of the motor 50.

In case the clutch 6 is operated in the system shown in Fig. 2, thecontact segment 17 is disengaged from contact terminals 18 and 19 tobreak the circuit from the battery portion'53a through the field winding52 and thus relieve the field winding ofl its additional excitation. l

In order to recharge the battery 53, the switch 61 is closed in thereverse position so that the switch blade 65 bridges the contactterminals 66 and 71 and the switch blade 63 bridges the contactterminals 68 and 72. A circuit-is completed which may be traced from thebattery-charging receptacle 73 through contact terminals 68 and 72,which are bridged by the switch blade 63, battery 53, and contactterminals 66 and 67, which are bridged by the switch blade 65, to thebattery-charging receptacle 73.

The circuit connections,v the arrangement windings, and adapted to drivea mechanical load, a source of propulsive energy theren for, and anauxiliary source of means for increasing the excitation of the fieldwind ing relative tothe armature winding from said auxiliary source incase the motor is relieved of said mechanical load.

Q. In a control system, the combination with a motor having series-woundarmature and field windings and adapted to drive a mechanical load and abattery for the motor comprising a main and an auxiliary source ofenergy, of means for connecting said auxiliary source ofenergy acrossthe field winding in case the motor is relieved of said load. l

3. In a control system vfor an electric vehicle, the combination with anelectric motor having armature and field windings gizing the motor', ofan auxiliary storage battery embodying a portion of said -main battery,and means for connecting said auxiliary storage battery across saidfield winding in case the motor is relieved of said load. f

5. In an electric vehicle, the combination with an electric motor havingseries-wound armature and field windings and a clutch for transmittingthe driving effort of the motor to the vehicle wheels, of means op-"erated by the clutch for controlling the excitation of the fieldwinding.

6. In an electric vehicle, the combination with an electric motor havingseries-wound 4,

armature and field windings and al clutch for transmitting the drivingeffort of the motor to the vehicle wheels, of means for increasing theexcitation of the field winding relative to 'the armature winding incase the clutch is released.

7. In an electric vehicle, the combination with an electric motor havingseries-wound armature and field windings, a storage battery comprising amain and an auxiliary source of energy for supplying energy thereto anda clutch for transmitting the driving effort of the motors to thevehicle wheels, of means controlled by the clutch for connecting theauxiliary source of energy in series with the field winding.

8. In an electric vehicle having a driving axle, the combination with aseries type motor having armature and field windings, a clutch forconnecting the motor to the driving axle and a source of energy for saidmotor, of means for increasing the excita tion 'of the field windingrelative to the armature winding in case the clutch is released and themotor is relieved of the load thereon.

9. In' an electric vehicle having a driving axle, the combination with amotor having series-wound armature and field windings and a main storagebattery for supplying energy thereto, a controller for governing theoperation of the motor and a clutch for connecting the motor to thedriving axle, ofan auxiliary storage battery embodying a portion of saidmain storage battery and means for connecting said auxiliary storagebattery across thefield Winding in case the 'clutch is released whilethe controller is in mitting means Vfor increasing the excitation of thefield winding relative to the armature winding. A

' 12. In anelectric vehicle, the combination with a main and anauxiliary source of energy, an electric motor having an armature and ayfield winding, and means for transmitting the driving effort of themotor to the vehicle wheels, of means Jfor operating said transmittingmeans and for connecting said auxiliary source in circuit4 with thelfield winding. f

13. In an electric vehicle, the combination withV a. main and anauxiliary source of energy, a'n electric motor having an armature and afield winding, and means for transmitting the driving effort of themotor to the vehicle wheels, of means active when said transmittingmeans occupies an inoperative position for-"increasing the excitation ofthe 'field winding from said auxiliary source.

In testimony whereof I have hereunto subscribed my name this 24th day ofApril,

THEODORE H. S'CHOEPF.

